Effects of Prebiotics and Probiotics on the Parasitic Microsporidium Nosema ceranae and Honey Bee (Apis mellifera) Health at the Individual and Colony Levels

Alternatives to fumagillin for the control of Nosema ceranae, an intestinal parasite of the honey bee, are needed. Fourteen compounds were screened at several doses for their control of N. ceranae in caged bees, and three were retested at their predicted optimal dose. Zymosan was the most successful at reducing N. ceranae spore numbers. In another study using field colonies, eugenol, Protexin® (Enterococcus faecium), chitosan and naringenin, were evaluated for their effects on N. ceranae and bee health parameters. Eugenol, naringenin and Protexin® reduced N. ceranae infections and increased honey production, while Protexin® also increased adult bee populations and eliminated colony winter mortality. Chitosan was ineffective. In general, compounds administered in protein patty worked better than in syrup in spring, whereas syrup worked better than patty in fall. For colonies, Protexin® was the most promising candidate for controlling N. ceranae and promoting honey bee health and productivity, warranting further investigation.